dev-go-concurrency-guide

name	dev-go-concurrency-guide
description	Développement Go avec focus sur la concurrence et les patterns idiomatiques. Se déclenche avec "Go", "Golang", "goroutine", "channel", "sync", "concurrency", "Go modules", "Go patterns", "interface Go". Also triggers on "Go goroutines", "channels in Go", "Go concurrency pattern".

Go Concurrency Guide

1. Fondamentaux Go — critères de décision

Situation	Choix
Méthode modifie le receiver	Pointer receiver *T
Méthode lit seulement	Value receiver T (sauf struct > ~64 bytes)
Comportement partagé	Interface implicite (duck typing)
Cleanup garanti	defer f.Close() / defer mu.Unlock()
Erreur attendue	Retour (T, error), jamais panic

type Store struct{ db *sql.DB }

func (s *Store) Get(ctx context.Context, id int) (User, error) {
    var u User
    err := s.db.QueryRowContext(ctx, "SELECT ...").Scan(&u.Name)
    return u, fmt.Errorf("store.Get %d: %w", id, err)
}

2. Goroutines et channels

Unbuffered = synchrone (handshake). Buffered = découplage, ne pas abuser.

done := ( {})
  {
     (done)
     {
         {
         <-ctx.Done():
            
         job := <-jobs:
            process(job)
        }
    }
}()


jobs := ( Task, )
 wg sync.WaitGroup
  N {                          
    wg.Add()
      {
         wg.Done()
         t :=  jobs { handle(t) }
    }()
}
(jobs)
wg.Wait()